CYNEGILS (d. 643)  , king of the West Saxons, succeeded his uncle King Ceolwulf in 6i1, With his son Cwichelm (d . 636), he defeated the advancing Britons at Bampton in Oxfordshire in 614, and Cwichelm sought to arrest the growing power of the Northumbrian king Eadwine by procuring his assassination; the attempt, however, failed, and in 626 the West Saxons were defeated in battle and forced to own Eadwine's supremacy .. Cynegils' next struggle was with Penda of Mercia, and here again he was worsted, the battle being fought in 628 at Cirencester, and was probably compelled to surrender part of his kingdom to Mercia . Cynegils was converted to Christianity through the preaching of Birinus, and was baptized in 635 at-Dorchester in Oxfordshire, where he founded a bishopric. lie was succeeded as king by his son Cenwalh .